1. Technical Field
The present invention relates to signal processing, and more particularly to an elastic client interface for a tunable optical transponder.
2. Description of the Related Art
Recent technology innovations in optical transponders have enabled the generation of a flexible modulation format and symbol rate, which leads to flexible bandwidth usage. Innovations in optical switches have enabled gridless optical spectrum switching which means the flexible selection of any frequency and any bandwidth. These innovations contribute to the paradigm of an elastic network, allowing service providers to satisfy the network's increasing needs without excessive investment.
An ideal elastic network requires one more feature to fully reflect the network needs: the spectrum usage shall be adaptive to the traffic capacity, not just the interface rate. However, the current interfaces with client networks are mostly fixed rate, and to ensure no traffic loss, the core network side of the optical transponder matches that fixed rate, irrespective of the actual throughput. This problem blocks the possibility to further reduce spectral utilization.
FIG. 1 shows a network environment 100 with fixed rate client interfaces 111, 112, and 113, in accordance with the prior art. The network environment 100 includes a flexgrid all-optical network 120, client networks 131 and 132, optical transponders 141, 142, 143, and 144, and the fixed rate client interfaces 111, 112, and 113. Disadvantageously, the client interfaces 111, 112, and 113 are fixed rate.